I, too, use Lagarith for PI, wish I could for Vegas. But .PNG is an OK alternative for me

>Quicktime-PNG compression does it.

If render to an image sequence, PNGs, the PNGs are opaque, no alphachannel. Or did you mean something else?
Ingvar

I used to do this with Quicktime PNG which worked well except for a bit of a black halo around the image. Through much experimentation and discussion on this forum, I determined that the problem was with Vegas and not Quicktime. No matter what codec I used for the encode, I would get the dark halo. I eventually gave up and now when I need to do this sort of thing I render the image onto a pure generated green background that I can key out easily. I do this keying with the New Blue Video Essentials keyer which gives you nice control over the edges.

I haven't tried rendering out alpha layer video in Vegas 10 though, so maybe this has been improved. I wouldn't count on it.

>If render to an image sequence, PNGs, the PNGs are opaque, no alphachannel. Or did you mean something else?

You have to right click on the clip on the timeline and adjust the properties to have the alpha layer disappear.

You have to tell particle illusion to save the alpha channel, and remove black BG from it.

Then it should work fine.

I would always suggest against using QuicktimePNG, as it's no different from using a .PNG seq, but if you want to change any one section or your computer shuts down for any reason during the render, you can't just re-start where it left off, you have to start at the beginning again.

Dave

oh, yes - Laurence is right about the black halo - no way to get rid of it in Vegas. Still, sometimes I can live with it, depending . . .

Like he says, I now usually render using New Blue directly from Vegas instead of to an alpha channel. Slower, but much cleaner result.

Laurence, I think you were doing something hinky in your video files, because if you are talking about videos from PI or anything else that outputs a proper alpha, I've never had this trouble, and I do plenty with alpha channels in Vegas, pushing .png sequences back and forth.

Dave

You have to right click on the clip on the timeline and adjust the properties to have the alpha layer disappear.

I am not sure what you mean.
In vegas 9, no problems preserving the alpha channel when rendering to PNGs. In Vegas 10, which I installed less than 20 hours ago, PNGs are opaque. What am I missing ???

Ingvar

Ok, it seems I must render 32 bit to get alpha PNGs in Vegas 10. In Vegas 9, 8bit also works. Has anyone else seen this?

I've never quite understood why Vegas doesn't let you render out an alpha channel to .AVI codecs like Lagarith and HuffyUV that clearly support one. I can render a Largarith AVI with an alpha channel from Particle Illusion and the very old Commotion Pro. These open fine in Vegas with the alpha channel intact. I've always wondered about this.

Yes, especially because it has no problems reading the Lagarith alpha channel.
The interesting thing to me at the moment, is why I cant render PNGs with alpha using Vegas 10. I must sett project pixel format to 32 bit. In vegas 9 I can render using 8 bit. Why is this?

I would always suggest against using QuicktimePNG, as it's no different from using a .PNG seq, but if you want to change any one section or your computer shuts down for any reason during the render, you can't just re-start where it left off, you have to start at the beginning again.

I forget if this was addressed in Vegas 9, but in 8 & before, image sequences took FOREVER to render out. A QT-PNG .mov file took a fraction of the time.

"Laurence, I think you were doing something hinky in your video files, because if you are talking about videos from PI or anything else that outputs a proper alpha, I've never had this trouble, and I do plenty with alpha channels in Vegas, pushing .png sequences back and forth."

I'm not Laurence (I'm Larry), but Laurence (and I) referred to the dark halo in alphas CREATED by Vegas. Alphas created by PI work flawlessly in Vegas; but no one ever has been known to get rid of the dark halos in the alphas created by Vegas. There was a thread on this problem a year or two ago . . .

I used to be Larry, but now I'm Laurence ;-) At some point in your life you want to stop using the diminutive. "Timmy" becomes "Timothy" and "Billy Bob" becomes "William Robert". I think it happens at exactly the same time as you realize that you aren't cute anymore.

Anyway, like my younger (likely) counterpart Larry says, Vegas is the culprit when it is creating alpha layer clips, not when it's playing them back. So if you want to use a chroma-key plugin in Vegas and save the result as a clip with a transparent alpha layer, you are going to have a black halo around the image regardless of the program you play it back with. If you use Vegas to edit an alpha layer clip created with some other program, you'll be fine.

Like a number of other people here, I had to learn about this the hard way. You don't really notice it on a low resolution preview. It's when you render out your final project at full HD resolution that this will drive you mad. I discovered this after I had separated a number of talking heads from their green backgrounds and couldn't get rid of the black halos any way except for rendering them onto a generated green background and keying that away with a little extra edge reduction. It's just one of those things you have to live with when you use Vegas.

Now I just either commit to a backdrop when I chromakey, or use a generated perfect green background that I can easily key out perfectly later with Cineform. It really works well. Cineform with a chromakey filter previews smoother than Quicktime PNG or Lagaryth anyway.

I'm terribly confused as to why you are keying in Vegas, and rendering alpha enabled scenes, rather than just keying in your final compositor. For that matter, why not just render the BG in there with Vegas on the original clip?

Perhaps you have some need to not use your final compositor to do your chroma keying, but if I want to do my final key in something else, I take ( for example ) EX-1 footage from client shot in front of greenscreen, cut the sequence I need with a little head and tail if my cuts aren't final in Vegas, render back out to EX-1 matching template ( no-recompress render ), and open that single clip in my compositor to do the keying and whatever comps I can't do in Vegas adequately.

Is there some reason that this can't also work for you?

Dave

Why not key in Vegas? The stock keyer isn't that great, but the New Blue Video Essentials keyer is fine. The quality is great as long as you don't try to save an alpha separation from Vegas.

>I'm terribly confused as to why you are keying in Vegas, and rendering alpha enabled scenes, rather than just keying in your final compositor.

To save time! I did my first pro job recently, talking head in front of various backgrounds. I first renderd out video files with him keyed out in After Effects. The material was approx 20 minutes long altogether. It took my computer 5 hours to key the person out (I did a batch render). Kyelight 2, various Red Giant Key Correct filters, one levels filter etc.

I can do the same now in Vegas, in minutes not hours, thanks to Boris BCC7. But I must then continue my work in After Effects, for many reasons.

When it comes to PNGs with alpha, there is no halo whatsoever, they are just fine on my machine. I just would like to know why I must render 32 bit to get alpha in PNGs in Vegas 10.. Is it only me?

Ingvar